Brain pathology
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Global cerebral blood flow (GCBF) is low in the human neonate compared to the adult. It is even lower in mechanically ventilated, preterm infants: 10-12 ml/100 g/minute, a level associated with brain infarction in adults. The reactivity, however, of global CBF to changes in cerebral metabolism, PaCO2, and arterial blood pressure is normal, except following severe birth asphyxia, or in mechanically ventilated preterm infants, who subsequently develop major germinal layer hemorrhage. ⋯ Two clinical patterns of brain damage following asphyxia may be explained by changes in the blood flow distribution induced by asphyxia: brainstem sparing and parasagittal cerebral injury. Hours to days after severe asphyxia, a state of marked global hyperperfusion may prevail. It is associated with poor neurological outcome and may be an entry point for trials of interventions aiming sat blocking the translation of asphyctic injury to cellular death and tissue damage.